Keralup (formerly Amarillo) Masterplan, Karnup

Department of Housing and Works

Advice of the Environmental Protection Authority to the Minister for the

Environment under Section 16(e) of the Environmental Protection Act 1986

(This is not an assessment of the Environmental Protection Authority under Part IV of the Environmental Protection Act 1986)

Environmental Protection Authority Perth, Western Australia

Bulletin 1281 4 March 2008

Report Released: 4 March 2008 Section 16 advice does not result in environmental approval. The process is intended to allow the EPA to provide advice on any environmental impacts associated with the Project at a strategic level. After receiving the advice of the EPA, Government will then decide if the Project will proceed. If it is to proceed, the proposal developed would be subject to formal environmental impact assessment. There is no appeal period on s16(e) advice.

Summary and Recommendations This report provides the Environmental Protection Authority’s (EPA’s) advice to the Minister for the Environment under section 16(e) of the Environmental Protection Act 1986 on the project by the Department of Housing and Works (DHW) to develop a new town site at Amarillo, a farming property in Karnup. Amarillo has subsequently been renamed Keralup. The project covers 4000 hectares in the single ownership of the DHW and lies 17 kilometres (km) south east of Rockingham and 10km north east of Mandurah. If developed, the area would become a fully integrated urban community housing up to 90 000 people. A Steering Committee was formed to develop a contemporary Masterplan for Government to develop this land through the DHW. A formal approach was made by the Minister for Housing and Works requesting strategic advice from the EPA on the proposed residential development. The EPA has been asked to define the key environmental factors affecting the proposed development and any further environmental investigations that may be required. As the Keralup Masterplan is of a more strategic nature with the requirement for more specific investigations highlighted, there is more than the usual level of uncertainty in making predictions of potential environmental impacts from what has been proposed in the Masterplan document. In addition, in some cases there is limited data available from a Western Australian context to inform any predictions of future impacts. However overarching advice can be provided on the concept of residential development as put forward in the Masterplan. The EPA has identified significant environmental constraints for development of the Keralup Site. The significant environmental issues identified for this proposed development include:

1. Surface and Groundwater– protection and management of all water resources on site including the risk of a further decrease in water quality from nutrient loads and potential downstream impacts in the Peel-Harvey catchment.

2. Wetlands – direct and indirect impacts on conservation value wetlands and their buffers within the proposed Keralup development site.

3. Remnant Vegetation – direct impacts on conservation value remnant vegetation within the proposed Keralup development site.

4. Soil and Groundwater Contamination – Potential for Acid Sulfate Soils (ASS), and potential contamination from former agricultural activities.

5. Significant Fauna – indirect impact on important habitat for State and Commonwealth listed threatened species.

6. Noise – direct impact of adjacent land uses including a Piggery, Airfields, the Perth-Bunbury Highway and Kwinana Freeway extension, on future residents within the proposed Keralup development site.

7. Odour - direct impact of adjacent land use on future residents within the proposed Keralup development site.

i

8. Mosquitoes – On-site and regional health impacts on future residents within the proposed Keralup development site.

There are significant issues of managing water quality and drainage within the Masterplan area that have not been addressed at this time. The assumptions made on improving water quality not only on-site but within the Serpentine River are not supported by technical modelling or within relevant Western Australian scientific literature. Current research points to a likely significant increase in the application of fertiliser and hence nutrient loading of the Serpentine River and the Estuary due to the urbanisation of the catchment. Therefore, to ensure that the water quality targets set out in the draft WQIP are not exceeded it is the EPA’s expectation that there would be no net export of nutrients from the Keralup site.

The concept of using a constructed wetland to reduce significantly the nutrient load in the Dirk Brook and therefore in the Serpentine River is also not supported by current Western Australian research. Considering the likely increase in phosphorus input under an urban zoning, studies suggest that any phosphorus reduction provided by a constructed wetland along the Dirk Brook may be negligible. In addition, it is anticipated that despite the removal of all current nutrient load, water quality will not significantly improve for another 20-50 years due to the historical nutrient soil store on-site. This is likely to cause a significant amenity issue for residents living adjacent to the Serpentine River as the frequency and severity of algal blooms may increase.

Managing drainage across the site also poses a significant challenge. Paradoxically, following drainage/stormwater best practice within the Masterplan area has the potential to increase existing water quality issues within the Serpentine catchment and the broader Peel-Harvey Estuary. Within this context, it is imperative that all surface and groundwater studies relating to drainage and nutrient management on site are completed in advance of any further planning. The collection of baseline data would be essential to accurately determine the feasibility of any urban development on this site. Available information suggests that that the current export of nutrients from the Keralup site will significantly increase should this property be rezoned and developed for urban purposes. Even taking into account the Dirk Brook Living Stream Concept, there will still be a net export of phosphorus and other nutrients to the Serpentine River which is not considered acceptable in terms of achieving a reduction under the draft WQIP. Because of the unique conditions on this site including historical nutrient loads in the soil, soils that have a low capacity to retain nutrients and a waterlogged soil profile, standard development methodologies if applied to this site would not achieve the water quality objectives set out in the draft Water Quality Improvement Plan (WQIP). An innovative approach to solving these critical issues would be essential to reach an acceptable outcome. In relation to the other environmental issues relevant to the proposed development such as wetlands, remnant vegetation, soil and groundwater contamination, significant fauna, noise and odour, further investigations would be required to determine whether

ii

development is appropriate for some areas of the site. In particular, possible land use incompatibilities with surrounding land uses such as a piggery and several airfields could impact on the health and amenity of future residents and could preclude development from portions of the Masterplan area which may affect the form of development and this in turn may have consequential impacts on broader design objectives for the future Keralup. Should Government decide to develop this site then further substantial environmental investigations would need to be carried out as well as extensive liaison with all relevant technical agencies. The table below summarises the key environmental issues, policy context and EPA position identified in the EPA’s consideration of the Masterplan and Environmental Appraisal documents as well as extensive consultation with relevant experts within the Department of Environment and Conservation, Department of Water and Department of Health. Column 1 specifies each environmental issue being considered. Column 2 outlines key policy and guiding documents which may contain policy positions or methodology for assessing the significance of impacts and guiding decisions on developments. Column 3 highlights further site specific investigations required to inform whether development of this site is environmentally feasible and if so how it may occur. Column 4 states the EPA’s position in relation to relevant policy and provides guidance on the opportunities and constraints for development. Environmental Issues

Policy Context / Guiding Documents

Further Investigations

EPA Position

Surface and Groundwater

• Environmental Protection (Peel Inlet – Harvey Estuary) Policy 1992.

• Draft Water Quality Improvement Plan 2007(WQIP).

• Regional Arterial Drainage Strategy.

• Local groundwater modelling.

• Local hydrologic and hydraulic. surface water modelling.

• Water Quality analysis.

• Flood Plain study.

• The draft WQIP specifies that significant reductions in phosphorus export to the Serpentine River is required.

• The prevailing conditions on this site including high water table, poor nutrient capacity of soils and proximity to water bodies poses significant challenges for urban development.

• In order to achieve the draft WQIP objectives in relation to phosphorus and other nutrients any development would need to demonstrate no net export of nutrients.

Wetlands • Environmental Protection (Swan Coastal Plain Lakes) Policy 1992.

• EPA Position Statement No. 4 – Environmental Protection of Wetlands.

• Wetland evaluation. • Wetland buffer

evaluation. • Wetlands

management plans.

• Conservation value wetlands and their buffers must be protected.

• Security of tenure of conservation value wetlands must be defined.

Remnant Vegetation

• Environmental Protection (clearing of native vegetation) regulations 2004.

• Comprehensive flora and vegetation survey.

• Conservation value remnant vegetation must be protected.

iii

iv

Environmental Issues

Policy Context / Guiding Documents

Further Investigations

EPA Position

• EPA Position Statement No.2 - Environmental Protection of Native Vegetation in Western Australia.

Soil and Groundwater Contamination

• Contaminated Sites Act 2003.

• Western Australian Planning Bulletin No. 64 Acid Sulfate Soils.

• Specific soils and groundwater sampling and analysis.

• Management plans where necessary.

• Specific soil and groundwater investigations must be carried out to identify level of risk

• The integrity, ecological function and environmental values of the soil and groundwater must be protected

Significant fauna • Environment Protection and Biodiversity Conservation Act 1999.

• Wildlife Conservation Act 1950.

• Targeted surveys for significant fauna.

• Management plans where required.

• Significant fauna and their habitat must be protected through appropriate planning mechanisms.

Noise • Environmental Protection (Noise) Regulations 1997.

• Specific noise modelling studies to define potential for noise disturbance for future residents.

• The amenity of any future residents must be protected from the noise impacts from adjacent land use activities.

Odour • Interim Guidance Statement No. 47 on Odour as a relevant Environmental Factor.

• EPA Guidance Statement No. 3 - Separation Distances between Industrial and Sensitive Land Uses.

• Specific odour modelling should be undertaken to define potential for impact on future residents.

• The amenity of any future residents must be protected from odour nuisance from any adjacent land use activities.

Mosquitoes – Onsite and Regional

• Guidance Statement No. 40 – Management of Mosquitoes for Land Developers.

• Assessment of mosquito risk to future residents needs to be undertaken.

• Management plan where required.

• The health and amenity of any future residents must be protected from mosquitoes without adversely affecting the environment.

• Chemical control of mosquitoes must not have an adverse affect on the environment.

Contents Page

Summary and Recommendations..................................................................................... i

1 Introduction.............................................................................................................. 1

2 Context for Evaluation ............................................................................................ 1

3 The Project ............................................................................................................... 2

4 Previous Environmental Assessment ..................................................................... 2

5 Primary Environmental Issues ............................................................................... 4

5.1 Surface and Groundwater ................................................................................. 5

5.2 Wetlands ......................................................................................................... 11

5.3 Remnant Vegetation........................................................................................ 17

5.4 Soil and Groundwater Contamination ............................................................ 18

5.5 Significant Fauna ........................................................................................... 21

5.6 Noise .............................................................................................................. 22

5.7 Odour ............................................................................................................. 25

5.8 Mosquitoes - Onsite and Regional................................................................. 27

6 Summary of Key Issues, Policy Context and EPA Position ............................... 28

7 Other Advice/Future Studies ................................................................................ 29

7.1 Requirement for construction materials.......................................................... 29

7.2 Requirement for site works............................................................................. 30

7.3 Karnup – Dandalup Ground Water Source Area ............................................ 30

7.4 Protection of the Serpentine River.................................................................. 30

8 Conclusion .............................................................................................................. 31

Figures Figure 1: Location Map Figure 2: Wetland Classifications Figure 3: Geomorphic Wetland Management Categories Figure 4: Environmental Protection (Swan Coastal Plain Lakes) Policy (1992)

Wetlands Appendices Appendix 1: References

1 Introduction This report provides the Environmental Protection Authority’s (EPA’s) advice to the Minister for the Environment under section 16(e) of the Environmental Protection Act 1986 (EP Act) on the proposal by the Department of Housing and Works (DHW) to develop a new town site at Amarillo, a farming property in Karnup. Amarillo has subsequently been renamed Keralup. The project covers 4000 hectares (ha) in the single ownership of the DHW and lies 17 kilometres (km) south east of Rockingham and 10km north east of Mandurah. If developed, the area would become a fully integrated urban community housing up to 90 000 people. A proposal to develop 3980ha for residential development at Amarillo was referred to the EPA in February 1995. The level of assessment was set at Public Environmental Review. The Public Environmental Review report was made available for public comment between 22 July 1996 and 16 September 1996. The then Minister for the Environment issued Statement 473 that the proposal could be implemented in April 1998 however the development was not implemented and the existing approval was not renewed. It expired in 2005. A Steering Committee has since been formed to develop a contemporary Masterplan for Government to develop this land through the DHW. A formal approach was made by the Minister for Housing and Works requesting strategic advice from the EPA on the proposed residential development. The EPA has been asked to define the key environmental factors affecting the proposed development and any further environmental investigations that may be required. After the EPA has published its advice, Government will then make a decision on proceeding to the next stage of obtaining statutory environmental and planning approvals. This second stage environmental assessment is expected to be referred as to the EPA in accordance with the requirements of the EP Act as either a section 38 referral of a proposal or under section 48A as amendments to the Region Scheme and Local Planning Scheme would also be required.

2 Context for Evaluation The Masterplan area falls within the Serpentine River sub-catchment with outflows from the proposed development area flowing to the Peel-Harvey Estuary. This catchment is listed for protection under the Peel-Harvey Estuary Environmental Protection (Peel Inlet-Harvey Estuary) Policy 1992 (Peel-Harvey Estuary EPP). The purpose of the Peel-Harvey Estuary EPP is to:

a) set out environmental quality objectives for the Estuary which if achieved will rehabilitate the Estuary and protect the Estuary from further degradation; and

b) to outline the means by which the objectives for the Estuary are to be achieved and maintained.

1

2

The environmental quality objectives to be achieved and maintained in respect of the Estuary are a median load (mass) of total phosphorus flowing into the Estuary of less than 75 tonnes per annum with:

a) the median load (mass) of total phosphorus entering the Estuary from the Serpentine River being less than 21 tonnes;

b) the median load (mass) of total phosphorus entering the Estuary from the Murray River being less than 16 tonnes; and

c) the median load (mass) of total phosphorus entering the Estuary from the Harvey River and Drains being less than 38 tonnes.

More recently the draft Water Quality Improvement Plan for the Rivers and Estuary of the Peel-Harvey System 2007 (WQIP) has been prepared. The draft WQIP specifies environmental quality objectives for phosphorus within the Peel-Harvey catchment system. The draft WQIP affects the protection of the whole Peel-Harvey catchment area aiming to improve water quality by reducing phosphorus discharges from the catchment through changes to agricultural and urban practices and land use planning. The draft WQIP identifies the current status of phosphorus loads; identifies the environmental values of water bodies, and the water quality objectives that will protect these values. The water quality objectives in the draft WQIP are identical to the overarching statutory objectives set in the Peel-Harvey Estuary EPP for protection of the Peel-Harvey catchments.

3 The Project The project is located at Karnup between Rockingham and Mandurah, 6 km from the Coast. The project site is situated in the Southern Metro/Peel region (see Figure 1). The subject land is formally known as Lot 100 Stakehill Road, Lot 802 River Road and Lot 801 Karnup. It covers approximately 4000ha, in the single ownership of the DHW. The site is bounded to the north by Henderson Road, to the west by the proposed Kwinana freeway extension and the Serpentine River, and on the south by rural residential activities of Nambeelup and on the east by a high tension power line. The project aims to deliver a new fully integrated urban town site catering for up to 90,000 people. It aims to be self-sustaining through also delivering transit, employment and recreational activities. It is envisaged that approximately 1,000ha will be set aside for conservation and public open space.

4 Previous Environmental Assessment A proposal to develop 3980ha for residential development at Amarillo Farm was referred to the EPA in February 1995. The level of assessment was set at Public Environmental Review. The Public Environmental Review report was made available for public review between 22 July 1996 and 16 September 1996. The then Minister

Figure 1: Location Map

3

for the Environment issued Statement 473 that the proposal could be implemented in April 1998, however the development was not implemented and the existing approval was not renewed. It expired in 2005. During 2006, the DHW commissioned a review of the proposed urban development. Since assessment of the previous development plans for Amarillo in 1997, further environmental issues relevant to urban development such as acid sulfate soils, as well as changes to contemporary management of environmental issues have arisen. The purpose of the review was to provide a description of the environmental attributes of the study area and to identify any possible opportunities and constraints to urban development. The review conducted in 2006 culminated in the preparation of the current Masterplan which is the subject of this EPA Section 16 (e) advice.

5 Primary Environmental Issues The EPA has identified significant environmental constraints for development of the Keralup Site. In the EPA’s opinion the following are the environmental issues relevant to the project depicted in the Masterplan:

1. Surface and Groundwater– protection and management of all water resources on site including the risk of a further decrease in water quality from nutrient loads and potential downstream impacts in the Peel-Harvey catchment.

2. Wetlands – direct and indirect impacts on conservation value wetlands and their buffers within the proposed Keralup development site.

3. Remnant Vegetation – direct impacts on conservation value remnant vegetation within the proposed Keralup development site.

4. Soil and Groundwater Contamination – Potential for Acid Sulfate Soils (ASS), and potential contamination from former agricultural activities.

5. Significant Fauna – indirect impact on important habitat for State and Commonwealth listed threatened species.

6. Noise – direct impact of adjacent land uses including a Piggery, Airfields, the Perth-Bunbury Highway and Kwinana Freeway extension, on future residents within the proposed Keralup development site.

7. Odour - direct impact of adjacent land use on future residents within the proposed Keralup development site.

8. Mosquitoes – On-site and regional health impacts on future residents within the proposed Keralup development site.

The above issues were identified through the EPA’s consideration and review of all environmental issues identified within the Masterplan and Environmental Appraisal documents as well as extensive consultation with relevant experts within the Department of Environment and Conservation (DEC), Department of Water (DoW) and Department of Health (DoH). Details of these issues and any further investigations required are contained in Sections 5.1 to 5.7.

4

5.1 Surface and Groundwater Description The integrated management of water (both surface and groundwater) will play a major role in the potential future development of the Masterplan area due to the nature of the soil and groundwater at the site, proximity to sensitive water bodies such as the Serpentine River and Lake Amarillo and its location within the coastal plain catchment of the Peel-Harvey Estuary catchment. The Masterplan area is generally low lying with many areas prone to water logging due to shallow depth to groundwater. Surface waters in the coastal catchment of the Peel-Harvey Estuary including the Masterplan area typically contain very high levels of the nutrients phosphorus and nitrogen. Nutrient loads originate from both diffuse and point sources directly related to predominant land uses in the catchment such as broad acre grazing, intensive agriculture and more recently rapid urbanisation. As a result of historical nutrient input in the Peel-Harvey Estuary and catchments, there are large stores of nutrients in the soils and sediments that will take years to leach out of the soil profile. The nutrient retention ability of these soils is very low and nutrients are easily leached through and across the soil structure (Kelsey, 2005, Summers et al, 1999). These nutrient stores contribute to the overall water quality concerns of the larger Peel-Harvey catchment. The primary delivery mechanisms for these contaminants are the extensive drainage network and groundwater discharge into the Peel Harvey Estuary and eventually the near shore coastal environment. The ecological impacts of this process has been widely documented and include persistent toxic algal blooms, deoxygenation events, and the occurrence of massive fish kills within the Serpentine River immediately downstream of the study area (Humphries et al, 1995). It is therefore critical that the surface and groundwater discharging from the site into the Serpentine River is managed effectively to ensure that the Water Quality objectives and load reduction targets set in the draft Water Quality Improvement Plan (WQIP) are met. EPA Objective and Policy Context The EPA’s objective in relation to Surface and Groundwater is to maintain the quality and quantity of water so that existing and potential environmental values including ecosystem maintenance are protected. The draft WQIP aims to improve water quality by reducing phosphorus discharge from the catchment through changes to agricultural and urban practices and land use planning. Both the draft WQIP and the Environmental Protection (Peel Inlet-Harvey Estuary) Policy 1992 specify environmental quality objectives for phosphorus at a sub-catchment level that includes the proposed Keralup development area.

5

Surface and subsurface runoff from the proposed Keralup development will enter the Serpentine lakes, some of which are protected under the Environmental Protection (Swan Coastal Plain Lakes) Policy 1992. The majority of these are freshwater bodies and are likely to be phosphorus limited in terms of algae growth. Therefore it is relevant to describe nutrient reductions, inputs and best management practices in terms of phosphorus for the proposed Masterplan development area. No performance standards (target loads or concentrations) have been set for nitrogen for the Peel-Harvey system at this time, however it is understood that the growth of algae in much of the Peel-Harvey is nitrogen limited. It is likely that performance standards for nitrogen will be addressed as part of future catchment management planning for the Peel-Harvey Estuary and should be included in any future planning for the Masterplan area. Environmental Issues Progressive nutrient enrichment of the Peel Harvey Estuary over several decades of catchment land use practices has contributed to declining estuarine and riverine water quality and the appearance of large accumulation of macro-algae and blooms of toxic blue-green micro-alga. The ecological impacts of these blooms have been widely documented and include bacterialogical scums, deoxygenation events, fish kills and the unsightly episodic decomposition of alga producing offensive odours including within the Serpentine River immediately downstream of the Masterplan study area. The Masterplan is cognisant of the issues relating to water quality issues as they pertain to the proposed development area. However, there are a number of critical assumptions that have been made in the Masterplan that will need further investigation. These are described below. Landuse Change from Agriculture to Urban Development One assumption within the Masterplan is that a change in land use from improved pasture to urban development would result in a decrease in the export of pollutants from the site. This assumption is not supported by current research. The DoW and the Department of Agriculture and Food have conducted research indicating that urban land use within Swan Coastal Plain catchments is a major contributor to nutrient export to waterways and estuaries (Kitsios and Kelsey, 2008) and that nutrient use is significantly higher in urban areas than for agricultural land uses such as improved pasture or grazing (Kitsios and Kelsey, 2008; Kelsey, 2001). Research shows that nutrient yields from urban catchments on the Swan Coastal Plain are greater than nutrient yields from land use that is predominantly agricultural in nature (Kelsey, 2001). Thus it is expected that further urban development would only increase nutrient export and is likely to worsen water quality (Kelsey, 2001; Zammit et al, 2005). The majority of the soil within the proposed Masterplan development area are part of the Bassendean Sands complex, and have an extremely low Phosphorus Retention

6

Index (PRI), which is a measure by which the soil can bind phosphorus, rendering it immobile and unable to run-off to the waterways. Therefore, the region is at a high risk for soluble phosphorus fertiliser to be conveyed either overland or through the sandy soil profile to the receiving water bodies. In addition, phosphorus stored in the soil profile in the Serpentine River catchment is estimated to be approximately 30% of the total phosphorus entering the Serpentine River (Zammit et al, 2006). Without any additional application of nutrients to the Peel-Harvey catchment, it is expected that there would still be a time lag for waterways to show a substantial improvement in phosphorus levels. It is possible that no significant improvements in catchment health or amenity would be seen within the draft WQIP timeframe of 10-30 years (EPA, 2007). The Serpentine River already exhibits major amenity issues in the form of fish kills, algal blooms and decay causing odours. This is likely to cause a significant amenity issue for residents living adjacent to the Serpentine River. The Masterplan recognises the river as an asset integral to the proposed development and an important component of the future vision for the area. There are a number of risk factors that influence the loss of nutrients from the landscape which include: closeness to drains or streams, water logging, nutrient retention capacity of soil, amount of phosphorus applied and how far it is from the estuary. In the context of proposed development in the Masterplan area, many of these risk factors are relevant suggesting that nutrient use and export may in fact increase adding to the already significant water quality issues within the Serpentine River and wider Peel-Harvey catchment and may considerably lengthen any recovery time. Living Stream Concept – Dirk Brook A major contributor to nutrient loads in the Serpentine River is Dirk Brook which runs through the property. It is proposed to use a ‘constructed wetland/living stream’ to reduce significantly the nutrient load in the Dirk Brook and therefore in the Serpentine River. The constructed wetland system would include modifying the narrow agricultural drain into a series of channels and wetlands to serve as treatment zones to reduce the flow of nutrients into waterways. Studies have been done in the eastern states and the USA regarding the effectiveness of water sensitive urban design (WSUD) including constructed wetlands, but there is limited data from Western Australia. Some studies have shown that constructed wetlands have limited capabilities in phosphorus reduction, particularly when phosphorus is in soluble form. Analysis of the water quality data in the Dirk Brook has shown that the soluble component of the phosphorus comprises approximately 58 percent of the total phosphorus, a figure that is much higher than for the eastern states where most phosphorus is in particulate form. This is linked to the extremely poor ability of the sandy soils in the region (Bassendean Sands) to bind the soluble phosphorus to the soil particles.

7

Studies examining the impact of urban development on water flows in the Southern River-Forrestdale-Wungong-Brookdale Structure Plan area found that phosphorus concentrations actually increased with the implementation of some WSUD’s (Kelsey and Zammit, 2003). This was due to the high concentration of phosphorus in subsurface flows from a soil profile saturated with phosphate. Elevated nutrient levels in the Dirk Brook are due to historic land use in the catchment and current levels of catchment remediation have been insufficient to improve water quality (Peta Kelsey, 2007 pers. comm). Data collected from the Leige Street constructed Wetlands points to insignificant nutrient reductions during discharge events after rainfall, when higher flows and nutrient loads occur, however up to a 45% reduction in nutrient levels under baseflow conditions, when lower flows and nutrient load can be achieved (GHD, 2007). The draft WQIP (2007) documents that within the Dirk Brook an estimated phosphorus load reduction of 82% would be required to meet the overall water quality objectives for the draft WQIP. Considering the expected increase in phosphorus input under an urban zoning, studies suggest that any phosphorus reduction provided by a constructed wetland along the Dirk brook may be negligible. Substantial further investigation would be required to determine whether the WSUD proposed would be effective in removing nutrients and meeting the water quality objectives set out in the draft WQIP. Drainage and Nutrient Management The EPA supports the design of drainage and nutrient management systems in accordance with the principles of best management practice as outlined in the Department of Water’s Stormwater Management Manual for Western Australia (2004-2007). The Masterplan area is generally low lying palusplain wetland with many areas prone to water logging due to the shallow depth to groundwater (See Figure 2). In addition, there is a substantial historical nutrient store in the soil that can easily be mobilised. Best management practice as documented in the DoW Stormwater Management Manual for Western Australia (2004-2007) advocates the retention and infiltration of all stormwater onsite where possible. In the context of the Masterplan area, following best management practice may in fact exacerbate the water quality issues on-site and within the broader catchment. Should planning for the development proceed, further investigation and liaison with the DoW would be required to determine what management techniques are most appropriate or even possible for this site.

8

Figure 2: Geomorphic Wetland Classifications

9

Further Investigations Due to the hydrologic conditions on this site it has been identified that surface and groundwater management will be a critical factor in determining the feasibility of this proposed development. The main areas of water resource assessment and management that remain outstanding for the proposed urban development in the Masterplan area are listed below and would be required prior to further planning for this site. Ground Water An extensive program to collect baseline ground water level and quality data would be required to enable the calibration of a local ground water model which would need to be developed from the DoW’s regional ground water model (PRAMS). The calibration of this model is crucial to enable the accurate prediction of the seasonal fluctuations in ground water level under both the current rural land use and an urban development scenario. The design of water management infrastructure, for non-potable uses and control of maximum groundwater levels, and the associated costs would be dependant upon the predictions of this modelling. Surface water assessment Similarly, an extensive program to collect surface water level, flow rates and quality data (including flow weighted nutrient loads) would be required to enable the calibration of local hydrologic and hydraulic surface water models. These models require input from the ground water model to enable the prediction of both flood and base flow rates and levels and the storage volumes and extent of land areas required to both compensate and treat urban stormwater and to protect the proposed urban development from flooding. Water quality management A detailed analysis of the existing surface and ground water quality would be required to make an assessment of the most appropriate structural and non-structural controls required for this part of the Swan Coastal Plain, utilising the research and guidelines that are currently being incorporated into the Stormwater Management Manual for Western Australia (Department of Water 2004-2007). Modelling of water quality under both a rural and urban scenario, in order to develop a nutrient budget for the site should also be undertaken in a manner that is consistent with the objectives of the Environmental Protection Authority’s “Draft Water Quality Improvement Plan” (WQIP) for the Peel Harvey Coastal Plain Catchment (2007). Floodplain management The current Serpentine River Flood Study would require a review based on the new assessments outlined above to ensure adequate protection of the proposed urban development up to the 100 year ARI event. This review would also need to consider the potential impacts of sea level rise due to climate change. Drainage management A Regional Arterial Drainage Strategy would need to be developed, incorporating all of the above assessment and management issues. The Department of Water and the Department for Planning and Infrastructure are currently drafting a framework to

10

integrate land use planning and water resources management which documents the requirements of such drainage strategies. The Department of Water and the Department for Planning and Infrastructure has commenced some district level investigations as part of the Urban Drainage Initiative project that may contribute to this process. It is recommended that the DHW liaises closely with the Department of Water in this respect. The Masterplan provides minimal recognition of the seriousness of the issues associated with drainage and nutrient management across this site and in the Serpentine River. Preventing any further reduction in water quality through the management of drainage and stormwater runoff should be viewed as a major environmental challenge with regards to the potential of this site for urban development. The Masterplan delivers a vision for urban development of a significant scale without any quantitative data, risk assessment or management plan for how these issues would be addressed. If planning for development proceeds, the collection of baseline data would be essential to accurately determine the feasibility of urban development on this site.

5.2 Wetlands Description Most of the Masterplan area is classified as palusplain (seasonally waterlogged flat) on the Department of Environment and Conservation (DEC) Geomorphic Wetlands Swan Coastal Plain dataset. There are smaller areas of dampland (seasonally waterlogged basin) and sumpland (seasonally inundated basin). There is also a significant area of river and floodplain including the Serpentine River, Lake Amarillo and Goegrup Lake. Geomorphic Wetlands on site are shown in Figure 3. The proposed development area contains areas of the Goegrup and Bennett Brook consanguineous wetland suites (Hill et all 1996). Wetland management categories have been assigned to the wetlands of the Swan Coastal Plain to provide guidance on the nature of management and protection the wetland should be afforded. The proposed development area is mapped on the DEC Geomorphic Wetlands Swan Coastal Plain dataset as Multiple Use. The dataset also shows a large area of Conservation Category wetlands which includes the riverine areas and 2 other Conservation Category wetlands are located to the east of the Serpentine River. There are 7 Resource Enhancement wetland areas within the Masterplan area. Four wetlands are subject to the provisions of the Environmental Protection (Swan Coastal Plain Lakes) Policy 1992 (Lakes EPP). Five wetlands subject to the provisions of the Lakes EPP are directly adjacent to the proposed development site and could be impacted upon by development. Wetlands protected under the Lakes EPP are shown in figure 4.

11

Figure 3: Geomorphic Wetland Management Categories

12

Figure 4: Environmental Protection (Swan Coastal Plain Lakes) Policy (1992)

Wetlands

13

EPA Objective and Policy Context The EPA’s environmental objective for wetlands is to maintain their integrity, ecological functions and environmental values. The Environmental Protection (Swan Coastal Plain Lakes) Policy 1992 was enacted to protect the environmental values of lakes on the Swan Coastal Plain. This Policy makes the filling, draining, excavating, polluting and clearing of these lakes an offence unless authorised by the EPA. The approach to wetland protection in Western Australia recognises three management categories – Conservation, Resource Enhancement and Multiple Use. The EPA considers all Conservation Category wetlands to be critical environmental assets that must be fully protected and conserved. The next priority is the protection of Resource Enhancement wetlands. The EPA urges and supports management measures directed at restoring the functions, structure and biodiversity of Resource Enhancement wetlands. Wetland protection requires appropriate protection and management of the adjoining buffer area. The EPA expects that the use of Multiple Use category wetlands will be considered in the light of ecologically sustainable development and best management practice catchment planning. It should be noted that critical assets as defined in the EPA’s Environmental Offsets Position Statement No. 9 (2006) also include Environmental Protection Policy wetlands regardless of management category. Environmental Issues Potential risks and pressures to wetlands and waterways from proposed development include:

• disturbance to wetland ecology due to filling of the palusplain wetland and encroaching development;

• disturbance to wetland ecology through changes to the site water balance; • impact on water quality through disturbance to nutrient store (nitrogen,

phosphorus or soils with acid potential during construction and dewatering activities;

• impact on water quality through lack of controlling suspended solids during construction and dewatering activities;

• removal of vegetation associated with a wetland or its buffer; • lack of appropriate management of wetlands with conservation value; • the potential for impact on wetlands where they form part of the drainage

network; and • disruption of natural processes associated with a riverine system.

Technical Accuracy The Masterplan has some minor technical inaccuracies. It has used a number of datasets which are now out of date or not in use.

14

1. The Masterplan depicts wetlands that were proposed to be protected under the Revised Draft Environmental Protection (Swan Coastal Plain Wetlands) Policy and Regulations 2004, which was not gazetted. Wetlands identified for protection under the Environmental Protection (Swan Coastal Plain Lakes) Policy 1992 should be depicted to ensure protection and management.

2. The wetland mapping used to form the basis of environmental studies should

be the most current version of the DEC’s Geomorphic Wetlands Swan Coastal Plan dataset. At least one discrepancy exists between Figure 3 of the Environmental Appraisal and the datatset.

3. It is stated in the Masterplan that ‘Wetland areas that support native

vegetation are identified as Conservation (C) or Resource Enhancement (RE) wetlands’ (page 20). It should be noted that wetlands on the Swan Coastal Plain are assigned to management categories following the wetland evaluation process. Wetland evaluation is the process of assessing and documenting a wetland’s values by considering information about its attributes and functions, and is not limited to consideration of native vegetation.

4. The Environmental Appraisal and Masterplan address wetlands under the

heading of ‘Surface Water Bodies’ and repeatedly make reference to surface water bodies. Not all wetlands have surface water, for example, damplands and palusplains, therefore future documentation should refer to ‘Wetlands and waterways’.

Further Investigations Wetland Evaluation Both the Environmental Appraisal and Masterplan contain the recommendation that an assessment and re-evaluation of wetlands be undertaken and submitted to the DEC. Proposals to modify the Geomorphic Wetlands Swan Coastal Plain dataset are required to be submitted to DEC’s Wetlands Program in accordance with the Protocol for proposing modifications to the ‘Geomorphic Wetlands Swan Coastal Plain’ dataset (DEC 2007). Proposals to modify the dataset need to be submitted to the Wetlands Program with sufficient time to allow any changes to be incorporated into the dataset. All relevant studies should take into consideration that the optimum time for field studies is immediately after the main period of rainfall (generally September – November). Revisions to the layout of the site may be necessary to reflect any modifications to wetland management categories in the Geomorphic Wetlands Swan Coastal Plain dataset. Wetland Buffers Different wetland buffer requirements and policies apply to lentic wetlands and waterways. However, the summary of buffer requirements in the Masterplan does not distinguish between the buffer requirements for lentic wetlands and waterways.

15

The intended method for proposing appropriate wetland buffers is not stated. Wetland buffer studies should be undertaken and submitted to DEC for review. Wetland buffers should be defined in accordance with the objectives outlined in the Environmental Guidance for Planning and Development, draft Guidance Statement No. 33 (EPA 2005). It is recommended that the proponent’s consultant liaise with the Wetlands Program for further guidance on current methodologies before proceeding with wetland buffer studies. Proposed protection mechanisms The Environmental Appraisal and Masterplan documents do not identify the mechanisms by which wetlands of conservation significance and their buffers outside of the proposed Peel Regional Park would be protected. Appropriate mechanisms via scheme amendments or other alternatives should be specified. The proposal to incorporate wetlands into multiple use corridors that maintain and enhance ecological linkages is supported. However, given that multiple use corridors also facilitate stormwater management, recreation and other land uses, it should be demonstrated that wetlands and their buffers retained for ecological purposes in multiple use corridors are adequate and would be protected and managed in accordance with the management objectives outlined in the Environmental Guidance for Planning and Development, draft Guidance Statement No. 33 (EPA 2005). Proposed landform modifications It is stated in the Masterplan that ‘The eastern dunal landform may be retained as part of the overall landscape management plan for the estate which may result in the need to import fill material. However this can only be determined at a later stage of development detail’ (page 34). At least two of the north-south wetlands located in the eastern area of the site proposed for protection are basin landforms that exist in association with dunes. Removing the dunes has the potential to impact on the wetland values by altering wetland hydrological regime, water chemistry, habitat and other processes and functions. Conversely, in other areas of the site where fill is proposed, the adjacent wetlands and buffers may be impacted upon. Landform modifications that have the potential to impact on wetlands of conservation significance are not supported. It is recommended that studies be undertaken to identify and assess the potential impacts of excavation and fill in proximity to wetlands of conservation significance, including alterations to geomorphology and hydrological regime. Wetland buffer studies should be cross-referenced to identify wetland functions and processes supported by/associated with the dunes. It is recommended that these studies be undertaken prior to further detailed planning. Maintaining wetland hydrological regime during dewatering The Masterplan does not discuss whether dewatering has the potential to impact on the hydrological regime of wetlands of conservation significance. Further studies

16

should identify any potential impacts to Conservation and Resource Enhancement wetlands and how these impacts would be avoided or managed should dewatering occur. Wetland management Wetland management plans should be prepared for all wetlands retained for ecological purposes. The Environmental Protection Authority (EPA) Draft Guidance Statement No. 33 Environmental Guidance for Planning and Development (EPA 2005) provides detailed guidance regarding the information required in wetland management plans. The Masterplan is cognisant of the issues that could affect wetlands and their protection. Should planning for the development proceed, it would be important to accurately define all wetlands and their buffers, protect and manage them as part of the overall development of the site in accordance with EPA and DEC policy.

5.3 Remnant Vegetation Description The majority of the Masterplan site has been pasture cleared and used for grazing cattle over an extended period of time. The only remaining indigenous vegetation includes the fringing and riparian vegetation of the Serpentine River, wetland vegetation across the site, some individual paddock trees and areas of Banksia woodlands near the eastern boundary of the Masterplan area. EPA Objective and Policy Context The EPA’s objective in relation to flora is to maintain the abundance, diversity, geographic distribution and productivity of flora at species and ecosystem levels through the avoidance or management of adverse impacts and improvement in knowledge. Most of the remaining intact remnant vegetation is located along the floodplain of the Serpentine River, which has been identified as being regionally significant through the System 6 Report and recommended for designation as a Regional Park (area M108). Since the review of the original Amarillo structure plan through the EPA’s formal assessment process (Environmental Protection Authority, 1997), vegetation within the northern half of the site along the Serpentine has also been identified as having conservation value by Bush Forever ( Site 394) (WAPC, 2000). Environmental Issues The extensive clearing of the Swan Coastal Plain for agriculture and urban land use requires that any remnant vegetation be examined carefully and evaluated. Previous investigations of vegetation in the Masterplan area were largely performed at a broad scale and relied heavily on aerial photograph interpretation (ATA, 2006). In his report Trudgen (1993) concluded that due to significant reductions in the extent of

17

vegetation associations that occur on the property their conservation value is significant, with the degree of significance varying amongst remnants depending on the scarcity of each vegetation complex. A flora and vegetation survey of the Keralup site was conducted in November 2005 and was undertaken to describe vegetation type and condition on the property. The survey was not intended to be a detailed flora survey as the timing in November was not optimal for this task. A pre-survey review of the then Department for Conservation and Land Management’s database highlighted the possibility of a range of declared rare and priority flora on site as well as two threatened ecological communities also potentially being present. The Masterplan has not defined accurately the value of areas of remnant vegetation outside the proposed Regional Park boundary or indicated how such areas might be protected and managed. The proposal to incorporate remnant vegetation into multiple use corridors that maintain and enhance ecological linkages is supported. However, given that multiple use corridors also facilitate stormwater management, recreation and other landuses further planning should clearly demonstrate that significant vegetation would be retained for ecological purposes. In addition, the adequacy and functionality of associated ecological linkages running through the Keralup Site also need to be defined. Further Investigations The Masterplan is cognisant of the issues that could affect remnant vegetation on site. Should planning for the development proceed, it would be important to accurately define all areas of significant remnant vegetation and their buffers to ensure protection and management of these areas as part of the overall development.

5.4 Soil and Groundwater Contamination Description Acid Sulfate Soils Acid sulfate soils (ASS) are naturally occurring soils and sediments containing sulphide minerals, predominantly pyrite (an iron sulphide). In an undisturbed state below the watertable, these soils are benign and not acidic. Inappropriate disturbance of these soils, causing oxidation of the pyrites, can generate large amounts of sulphuric acid and leaching of contaminants naturally occurring in soils. Flushing acidic leachate to groundwater and surface waters can cause site impacts including:

• ecological damage to aquatic and riparian ecosystems; • contamination of groundwater with arsenic, aluminium and heavy metals; and • damage to infrastructure through the corrosion of concrete, steel and other sub

surface assets. The types of activities which may cause the oxidation of acid sulfate soils include, but may not be limited to:

18

• dewatering operations; • excavation or other soil disturbance; • groundwater abstraction for private or commercial water supplies; • groundwater level control by drainage; • dredging operations; and • land use changes which alter the water balance.

The mapping in the Western Australian Planning Commission’s (WAPC’s) Planning Bulletin 64 classifies the majority of the Keralup Site as a “moderate to low” risk of ASS occurring within 3 metres of the natural soil surface with a few defined areas predicted to a “high risk” of ASS. The areas defined as having a “high risk” of ASS generally correspond with the Serpentine River and its floodplain as well as the location of other smaller wetlands on site. Contamination Much of the Masterplan area was formally or is currently being used for agricultural purposes. Some agricultural activities have the potential to cause soil and groundwater contamination which may compromise the suitability of the site for residential development or require remediation. It would be important to assess whether areas may potentially be contaminated and if necessary determine the extent and severity of contamination on site. EPA Objective and Policy Context Acid Sulfate Soils The EPA’s objective for ASS is to ensure that remediation achieves an acceptable standard that protects the environment, is compatible with the intended land use, and is consistent with appropriate criteria set out by the DEC. Where there is a risk of disturbing acid sulfate soil, the EPA expects that the procedures outlined in Western Australian Planning Bulletin No. 64 Acid Sulfate Soils (WAPC 2007) will be followed. This Planning Bulletin sets out the information that should be provided and the procedures to follow, including seeking comments from DEC. Detailed guidance on site investigations and the preparation of acid sulfate soil management plans is provided in the DEC Acid Sulfate Soil Guidelines series. The current titles in this series are listed on the DEC website (www.dec.wa.gov.au). Contamination The EPA’s objective for Contaminated Sites is to ensure that remediation of site contamination achieves an acceptable standard that protects the environment, is compatible with the intended land use, and is consistent with appropriate criteria set out by the DEC.

19

The Contaminated Sites Act 2003 (Act) and the associated Contaminated Sites Regulations 2006 took effect on 1 December 2006. The Act provides a legal framework for the management of contaminated sites in Western Australia, and requires owners, occupiers and polluters to report known or suspected contaminated sites to DEC. DEC has also published series of administrative and technical guidelines to help with the identification, assessment, management and remediation of contaminated sites in Western Australia. The current titles in this series are located on the DEC website (www.dec.wa.gov.au). Environmental Issues Inappropriate disturbance of ASS has the potential to cause significant ecological and infrastructure damage. Preliminary investigations (Maunsell, 2006) undertaken in 2005/2006 indicated that potential areas where ASS may occur did not correlate well with the WAPC mapping and further detailed sampling and analysis was recommended to properly assess the risk of ASS across the site. As indicated above, the site has been previously used for a range of agricultural activities which have the potential to cause soil and groundwater contamination. It should also be noted that because of the presence of a known mineral sands orebody acidification poses an additional risk of heavy metal and radon release if dewatering and drainage in the area is not well managed. In addition, there is a lack of buffering capacity in underlying sediments and the presence of thick and extensive “coffee rock” layers beneath the site, all of which are risk factors for acidification if the water table is disturbed by construction dewatering and subsoil drainage. Should acidification of the soil occur, then the leaching of nutrients from the soil profile would increase which could also significantly contribute to the existing water quality issue with the Serpentine River and greater Peel Harvey Estuary areas (Appleyard, S, 2007, pers comm). Poorly managed urban development on similar sites in the metropolitan region has triggered groundwater contamination with the potential to cause significant environmental harm, and has led to one development being classified under provisions of the Contaminated Sites Act 2006 as a contaminated site. There is also a risk that acidification is already taking place in the area due to existing agricultural drainage and the prolonged period of below-average rainfall which is likely to have caused significant declines in the elevation of the regional water table. Further Investigations Should planning for the development proceed, then there is an expectation that all soil and groundwater investigations on the site would be undertaken in accordance with the relevant Contaminated Sites and ASS guidelines as well as the relevant Australian Standards on sampling and data management and risk assessment. If ASS materials

20

are found on site, it is expected that a comprehensive ASS management plan would be prepared indicating how soil and groundwater would be managed on the site. Specific soil and groundwater investigations should be carried out in accordance with the relevant ASS guidelines to provide the necessary information. However, additional sampling and leaching tests may be required to determine radiological risks at the site. It is recommended that both the DoH and the Radiological Council are consulted regarding human health risk assessments at the site due to the possible presence of radionuclides in underlying sediments. The Contaminated Sites guideline series provides general guidance and management advice in relation to contamination and ASS and can be found on the DEC website. Further detailed sampling and analysis is considered to be an essential part of future detailed planning for this site. There is currently insufficient information available to determine the significance of the risks posed by ASS or contamination on site. It is recommended that the risks associated with ASS, historical contamination and the prevailing soil conditions be properly assessed and quantified before planning for the development proceeds any further as changes to the development proposed within the Masterplan area may be required to manage them.

5.5 Significant Fauna Description The majority of the Masterplan area has been cleared of remnant vegetation and used for pasture grazing and other agricultural purposes over an extended period of time. Exceptions to this include the fringing and riparian vegetation along the Serpentine River, the north-south aligned wetlands and the remnant Banksia woodlands near the eastern boundary of the Keralup Site. Small stands of paddock trees also occur intermittently across the Masterplan area. A preliminary assessment by ATA Environmental has identfied the potential for 4 threatened species of fauna and 13 migratory species of birds listed under the Environment Protection and Biodiversity Conservation Act 1999 to occur within the Masterplan area. A further 4 species listed as threatened under the Western Australian Wildlife Conservation Act 1950 and 13 Priority species are potentially found within the vicinity of the project area. The Birds of Serpentine – Mandurah – Murray Bird Guide (Birds Australia 2005) lists sightings of 2 threatened species (Carnaby’s Black Cockatoo and Baudin’s Black Cockatoo) and four migratory species (Sharp-tailed Sandpiper, Curlew Sandpiper, Red-necked Stint and Common Greenshank) in nearby wetlands and pools of the Serpentine River.

21

EPA Objective and Policy Context The EPA’s objective is to maintain the abundance, diversity, geographic distribution and productivity of fauna at species and ecosystem levels through the avoidance or management of adverse impacts and improvement in knowledge. Activities that directly or indirectly impact on significant fauna or its habitat should be avoided. Environmental Issues Once numerous in Western Australia, the highly mobile Carnaby’s Black Cockatoo (Calyptorhynchus latirostris) is now listed as endangered, with populations declining dramatically due to land clearing for agriculture in regional areas and for urban development on the Swan Coastal Plain. The birds are most abundant in areas which contain a high proportion of pine plantations or areas of native bush and isolated paddock trees, including the Rockingham Peel Region area. Habitat loss and degradation is a significant threat to migratory waterbirds, and the conservation of these important sites is essential to their survival. These species require a wide range of habitats including wetlands, inter-tidal mudflats, sandflats and estuaries. Waterbirds can also be threatened by introduced species and disturbance of their feeding grounds (DEH, 2005) Further Investigations The potential for clearing of significant fauna habitat should be determined through site survey. Targeted surveys should be conducted specifically for the Carnaby’s Cockatoo, a range of migratory species and any other significant fauna within the proposed Masterplan area. The Masterplan has not determined the value of any local stands of terrestrial or riparian vegetation or paddock trees that may be valuable habitat, nesting or feeding grounds for significant fauna species. It would be important to undertake these investigations, including that they should occur in consultation with the Commonwealth Department of Environment, Water, Heritage and the Arts who administers the requirements of the Commonwealth Environment and Protection of Biodiversity Conservation Act 1999.

5.6 Noise Description Land uses with the potential for noise disturbance adjacent to the Masterplan area include the Wandalup Farms Piggery, the Serpentine Airfield, the Murrayfield Airpark, the proposed Perth – Bunbury Highway and the future Kwinana freeway extension. The Wandalup Farms Piggery operates on land adjacent to the southern boundary of the Keralup area and the Serpentine Airfield occurs north-east of the site boundary. In

22

addition to these two land uses, the Murrayfield Airpark to the south and the Proposed Perth-Bunbury Highway and future Kwinana Freeway extension to the west also pose potential noise disturbance risks for future residents. Transmission of noise to the proposed development from the piggery to the south would be favoured by suitable conditions and light southerly winds. These conditions are likely to occur in the evening and so the primary concern relates to noise disturbance from the piggery sheds during night feeding. The potential for noise disturbance from Serpentine Airfield was raised as an issue during public submissions of the 1997 environmental assessment. The primary noise concerns from the Serpentine Airfield result from the alignment of their landing strip in a north-east/south-west direction near the north-east edge of the property boundary. EPA Objective and Policy Context The EPA’s broad principle in relation to noise is to protect the amenity of the community from noise impacts associated with development or land use and to avoid unacceptable adverse impacts on the natural environment by ensuring that statutory requirements and acceptable standards are met. Activities that generate noise should be managed in accordance with the following order of preference:

1. Avoid activities that create noise and vibration. 2. Contain emissions within the individual land use site boundary. 3. Manage emissions so that there are no unacceptable noise and vibration

impacts on nearby land uses and the environment.

Environmental Issues A number of adjacent land uses with the potential to have noise impacts on future residents within the proposed Keralup residential development have been identified. These land uses include the:

• Serpentine Airfield; • Murrayfield Airpark; • Wandalup Farms Piggery; • Perth-Bunbury Highway; and • Kwinana Freeway extension.

Serpentine Airfield (north-east) The primary noise concerns from the Airfield result from the alignment of the landing strip in a north-east/south-west direction near the north-east edge of the property boundary. There is uncertainty as to whether noise from aircraft taking off or landing may result in a noise disturbance within the upper north-east corner of the property.

23

No indicative buffer has been provided as part of Figure 7 in the Masterplan. During the original assessment of Amarillo Farm in 1995, the then Department of Environmental Protection (DEP) conducted investigations that indicated that unacceptable noise impacts could extend up to 2 kms into the north-east corner of the Keralup site. The Masterplan has not included this investigation or any further investigations to define a noise buffer and depicts development extending well into this 2 km zone. In addition, activities at the Serpentine Airfield may have changed since the initial DEP investigation was conducted and therefore a site specific investigation is needed to properly assess current and future noise impacts Murrayfield Airpark The Masterplan does not appear to have considered any potential noise impacts from Murrayfield Airpark. A site specific investigation is needed to properly assess current and future noise impacts development. Wandalup Farm Piggery (south) No site specific study has been undertaken of noise impacts from the Wandalup Farm piggery, however, the environmental studies recommend that an indicative buffer of 5km is provided for land use planning purposes until this detailed study is undertaken. Such a buffer is considered appropriate for indicative planning and is appropriately marked as a development constraint in Figure 7 in the Masterplan however residential development is still depicted as occurring within this indicative boundary area. It is expected that site specific studies would be undertaken prior to pursuing development to properly assess the noise impacts. Perth-Bunbury Highway and the Kwinana Freeway extension The Masterplan does not appear to have considered any potential noise impacts from the Perth-Bunbury Highway or the Kwinana Freeway extension. A site specific investigation is needed to properly assess current and future noise impacts. In addition, Stage 1 of the indicative staging plan for development across the site is located directly adjacent to the Kwinana Freeway extension so traffic noise impacts would require early assessment. Technical Accuracy The environmental assessment undertaken by Bowman Bishaw Gorham in 1993 is now outdated and refers to previous noise legislation. The Environmental Protection (Noise) Regulations 1997 were gazetted after the report was prepared, therefore the original references are now inaccurate. Further Investigations There are a number of adjacent land uses which have the potential to impact on the proposed residential development of the Masterplan area. The Masterplan has not

24

identified any land use conflicts between the proposed residential development and adjacent land uses which could impact on the Keralup site. No specific land use buffers have been identified based on site studies to exclude development from areas where there may be significant noise concerns for any future residents. An early understanding of these impacts would be critical as they may dictate the extent or form of development and this in turn may have consequential impacts on broader design objectives for the future Keralup. As one example, the extent of areas to be developed may influence the ability to achieve density thresholds to support transport initiatives. Should planning for development proceed, any potential for noise disturbance from adjacent land uses would need to be defined at an early stage of the planning process.

5.7 Odour Description The Wandalup Farms piggery is one of the largest in Western Australia and lies to the south of the Keralup site. This property is currently licensed for 22,000 pigs annually and includes a waste treatment facility and a compost manufacturing facility. Wandalup Farms have recently made a significant investment in upgrading their waste water treatment system which is expected to have significantly reduced odour emissions from the wastewater ponds. However the nearest odour source to the Masterplan area, the pig sheds, were identified as a principle source of odour and would remain a difficult source to control. As a result odour emissions from the piggery and their impacts on nearby residences would remain a considerable constraint to urban development over the southern half of the site. EPA Objective and Policy Context Odour is consistently recorded as the cause of about one-third of all public complaints received by DEC. Most odour complaints received by the DEC against industry have centred on animal products processing activities and relate to:

• frequency of the odour occurrence; • intensity of the odour; • duration of the exposure to the odour; • offensiveness of the odour; and • location of the odour.

Odour is largely an amenity issue for residential and sensitive land uses. However, in some instances, odour may indicate an emission with health and/or ecological effects.

Advice on separation distances between sensitive land uses and land uses with odour emissions is provided in EPA Guidance Statement No. 3 Separation Distances between Industrial and Sensitive Land Uses (2005). The EPA recommends that generic separation distances are maintained unless adequate site-specific studies have been carried out that demonstrate that a lesser distance would not cause unacceptable amenity impacts.

The criteria in EPA Guidance Statement No. 47 Assessment of Odour Impacts from

25

New Proposals (EPA 2002e) were under review at the time of publication of this guidance statement. An interim Guidance Statement No. 47 on Odour as a relevant Environmental Factor is currently available on the EPA website (www.epa.wa.gov.au) Environmental Issues An analysis of potential constraints to urban development by the Wandalup Farms Piggery was conducted in 1993 (Bowman Bishaw Gorham,1993). Regional meteorological data indicated that wind conditions (primarily prevailing southerly winds) likely to allow detectable odour emissions from the piggery within the southern sections of the Keralup property occur once every 3-4 days. This was identified as a potential nuisance to future residents. Methods to address the constraint of odour emissions were identified as (Bowman Bishaw Goreham, 1993):

• applying a site specific odour impact assessment, involving; • assisting Wandalup Farms with the implementation of an upgraded odour

control program; and • negotiate a relocation of Wandalup Farms.

The consultants advised that in the interim, when considering development options, EPA Guidance Statement No.3 Separation Distances between Industrial and Sensitive Land Uses should be applied. The recommended separation distance between major piggeries and residential development area is 5 kilometres. The application of this buffer distance would preclude development of approximately 1,500 hectares of the Masterplan area. The Masterplan does not reflect this possibility within its initial figure as development is depicted to the boundary of the Masterplan area. Technical Accuracy Guidance Statement No.47 – Assessment of Odour Impacts from New Proposals has been withdrawn. EPA Guidance Statement No. 47 now called Interim Guidance on Odour as a relevant environmental factor is the applicable guidance to refer to. This guidance statement can be found on the DEC website (www.dec.wa.gov.au). Further Investigations Investigations must take adequate account of seasonal factors that influence emissions and/or impacts. This may or may not require studies to be undertaken at certain times of the year. For example, modelling must be undertaken using at least a year’s worth of meteorology to properly assess variability in climatic conditions. In addition, should site-specific studies be done, model selection and modelling must be undertaken in accordance with the DEC modelling guidelines “Air Quality Modelling Guidance Notes, March 2006”. The Masterplan raises the issue of odour from the Wandalup Piggery as a potential constraint however does not reflect this possibility in the overall Masterplan mapping for the Keralup. As described above in relation to noise, odour impacts may dictate

26

the extent or form of development and this in turn may have consequential impacts on broader design objectives for the future Keralup. Site-specific studies would need to be done to accurately determine the feasibility of urban development in its current form at this site.

5.8 Mosquitoes - Onsite and Regional Description Mosquitoes were identified by the EPA as a relevant environmental factor affecting Amarillo Farm during the public submissions phase of the previous environmental assessment, following a detailed submission by the then Health Department of Western Australia. This issue has again been raised as an issue of concern. The DoH has expressed concern that mosquito populations on and off site would seriously threaten the health and lifestyle of prospective residents. EPA Objective and Policy Context The EPA objectives in relation to the control of nuisance mosquitoes are to ensure that:

• mosquito numbers on-site and off-site do not adversely affect the health, welfare and amenity of future residents; and

• the breeding of mosquitoes is controlled to the satisfaction of the DoH without adversely affecting the environment.

Environmental Issues The following issues were raised in relation to Mosquitoes:

• there is a high risk of Ross River Virus and Barmah Forest Virus as well as severe nuisance from biting mosquitoes at this site;

• the close proximity of the subject land to extensive areas of natural salt marsh mosquito breeding habitat that is within dispersal range. In addition, natural wetlands on site and the proposal for constructed water bodies may further exacerbate the mosquito and mosquito-borne disease problems for future residents;

• freshwater mosquitoes move significant distances from their breeding sites and are not affected by vegetation barriers;

• Kangaroos are a host for the Ross River and Barmah Forest viruses and may remain in drainage corridors following urbanisation;

• during mosquito outbreaks experienced within the Peel Region during 2005-2006, chemical control of mosquitoes alone did not reduce the risk of disease to an acceptable level. Furthermore, it is unlikely that there will be advances in the chemical control of mosquitoes in the near future; and

• Chemical control can have a significant impact on fauna which could have implications for some significant species.

27

Further Investigations The Masterplan provides minimal recognition of the potential seriousness of the issues and has not provided any quantitative data, risk assessment or management plan for how this issue would be addressed. If planning for development proceeds, further assessment would be required and detailed consideration would need to be given to these issues, including appropriate consultation with the DoH and the DEC.

6 Summary of Key Issues, Policy Context and EPA Position

The table below summarises the key issues policy context and EPA position on these issues. Column 1 specifies each environmental issue being considered. Column 2 outlines key policy and guiding documents which may contain policy positions or methodology for assessing the significance of impacts and guiding decisions on developments. Column 3 highlights further site specific investigations required to inform whether development of this site is environmentally feasible and if so how it may occur. Column 4 states the EPA’s position in relation to relevant policy and provides guidance on the opportunities and constraints for development. Environmental Issues

Policy Context / Guiding Documents

Further Investigations

EPA Position

Surface and Groundwater

• Environmental Protection (Peel Inlet – Harvey Estuary) Policy 1992.

• Draft Water Quality Improvement Plan 2007(WQIP).

• Regional Arterial Drainage Strategy.

• Local groundwater modelling.

• Local hydrologic and hydraulic. surface water modelling.

• Water Quality analysis.

• Flood Plain study.

• The draft WQIP specifies that significant reductions in phosphorus export to the Serpentine River is required.

• The prevailing conditions on this site including high water table, poor nutrient capacity of soils and proximity to water bodies poses significant challenges for urban development.

• In order to achieve the draft WQIP objectives in relation to phosphorus and other nutrients any development would need to demonstrate no net export of nutrients.

Wetlands • Environmental Protection (Swan Coastal Plain Lakes) Policy 1992.

• EPA Position Statement No. 4 – Environmental Protection of Wetlands.

• Wetland evaluation. • Wetland buffer

evaluation. • Wetlands

management plans.

• Conservation value wetlands and their buffers must be protected.

• Security of tenure of conservation value wetlands must be defined.

Remnant Vegetation

• Environmental Protection (clearing of native vegetation) regulations 2004.

• EPA Position Statement No.2 - Environmental

• Comprehensive flora and vegetation survey.

• Conservation value remnant vegetation must be protected.

28

Environmental Issues

Policy Context / Guiding Documents

Further Investigations

EPA Position

Protection of Native Vegetation in Western Australia.

Soil and Groundwater Contamination

• Contaminated Sites Act 2003.

• Western Australian Planning Bulletin No. 64 Acid Sulfate Soils.

• Specific soils and groundwater sampling and analysis.

• Management plans where necessary.

• Specific soil and groundwater investigations must be carried out to identify level of risk

• The integrity, ecological function and environmental values of the soil and groundwater must be protected

Significant fauna • Environment Protection and Biodiversity Conservation Act 1999.

• Wildlife Conservation Act 1950.

• Targeted surveys for significant fauna.

• Management plans where required.

• Significant fauna and their habitat must be protected through appropriate planning mechanisms.

Noise • Environmental Protection (Noise) Regulations 1997.

• Specific noise modelling studies to define potential for noise disturbance for future residents.

• The amenity of any future residents must be protected from the noise impacts from adjacent land use activities.

Odour • Interim Guidance Statement No. 47 on Odour as a relevant Environmental Factor.

• EPA Guidance Statement No. 3 - Separation Distances between Industrial and Sensitive Land Uses.

• Specific odour modelling should be undertaken to define potential for impact on future residents.

• The amenity of any future residents must be protected from odour nuisance from any adjacent land use activities.

Mosquitoes – Onsite and Regional

• Guidance Statement No. 40 – Management of Mosquitoes for Land Developers.

• Assessment of mosquito risk to future residents needs to be undertaken.

• Management plan where required.

• The health and amenity of any future residents must be protected from mosquitoes without adversely affecting the environment.

• Chemical control of mosquitoes must not have an adverse affect on the environment.

7 Other Advice/Future Studies

7.1 Requirement for construction materials The development of this area would require substantial volumes of fill to be imported to ensure that infrastructure is protected from inundation and to achieve nutrient management. Obtaining substantial quantities of fill could have flow-on environmental consequences. The Masterplan documents that sufficient fill material is available within the Masterplan area however no indication has been given as to the suitability of these soils for this purpose. In light of water quality issues on site

29

including low nutrient retention capacities and the potential for acid sulfate soils, use of fill material from within the Masterplan area would need detailed investigation. It is understood that there are limited supplies of sand and limestone fill materials available in the Perth metropolitan region. The requirement for large volumes of materials would impact on the availability of local materials and may bring forward the need to identify and develop new extraction areas. Many sites that contain underdeveloped limestone and sand resources in the metropolitan region occur in locations where planning and environmental constraints, such as Bush Forever Sites and noise and dust amenity issues, may preclude or severely constrain extraction. The EPA would not support the clearing of remnant vegetation to access basic raw materials. It would be important to investigate an appropriate source of sand and clearly document this source for any future assessment of this site. This situation may provide an opportunity to investigate the use of recycled materials, including construction and demolition waste, as a source of fill.

7.2 Requirement for site works The Masterplan highlights the need for cut and fill as well as dewatering during construction activities. The acceptability of using fill won from the Masterplan area remains in question because of the presence of acid sulfate soils and the effectiveness of the sands found within the Masterplan area to manage nutrients.

7.3 Karnup – Dandalup Ground Water Source Area The proposed Karnup Dandalup GWSA is a proposed Public Drinking Water Source area (PDWSA) similar to Jandakot and Gnangara. The DoW is currently carrying out a review to determine if this water source is viable for public consumption. The completion of the review is expected mid 2008 and the DoW would then be able to determine whether further investigation is required (ie drilling exploration bores, modelling, amending area's boundary, etc). If further investigations determine that the water source area is viable, then the area will be gazetted. Until such time as this occurs, the DoW has advised that it expects that any rezonings and land use proposals takes into consideration the PDWSA and is assessed against compatible land uses found in the table of the water quality protection note. No buffers are required around the source area. However, at the later stage if and when it is gazetted, there would be well-head protection zones around the extraction bores where special provisions would apply (ie storage of fuels, manures, etc) and managed under the bylaws of the Metropolitan Water Supply Sewerage and Drainage Act 1909 or Country Areas Water Supply Act 1947.

7.4 Protection of the Serpentine River The draft WQIP highlights the need for certain management measures and control actions required across the Peel-Harvey catchment, including the Serpentine River, to reduce phosphorus input into the Estuary. It is acknowledged that the draft WQIP is a long term plan and no significant changes in water quality could be seen for the next 20-50 years.

30

The development caters for a possible 90,000 people urban development. The Serpentine River already exhibits major amenity issues in the form of fish kills and algae blooms and decay. There are also health and lifestyle issues of concern in the form of high levels of mosquitoes carrying a range of diseases. In light of these facts and the proposed development timeframe for the Keralup development being in the order of 5-10 years, there may be a need for Government to focus efforts on the clean up of the Serpentine River catchment within a shorter timeframe than the draft WQIP is proposing to deliver.

8 Conclusion As the Keralup Masterplan is of a more strategic nature with the requirement for more specific investigations highlighted, there is more than the usual level of uncertainty in making predictions of potential environmental impacts from what has been proposed in the Masterplan document. In addition, in some cases there is limited data available from a Western Australian context to inform any predictions of future impacts. However overarching advice can be provided on the concept of residential development as put forward in the Masterplan. The EPA has identified significant environmental constraints for development of the Keralup Site. The significant environmental issues identified for this proposed development include: 1. Surface and Groundwater– protection and management of all water resources on

site including the risk of a further decrease in water quality from nutrient loads and potential downstream impacts in the Peel-Harvey catchment.

2. Wetlands – direct and indirect impacts on conservation value wetlands and their buffers within the proposed Keralup development site.

3. Remnant Vegetation – direct impacts on conservation value remnant vegetation within the proposed Keralup development site.

4. Soil and Groundwater Contamination – Potential for Acid Sulfate Soils (ASS), and potential contamination from former agricultural activities.

5. Significant Fauna – indirect impact on important habitat for State and Commonwealth listed threatened species.

6. Noise – direct impact of adjacent land uses including a Piggery, Airfields, the Perth-Bunbury Highway and Kwinana Freeway extension, on future residents within the proposed Keralup development site.

7. Odour - direct impact of adjacent land use on future residents within the proposed Keralup development site.

8. Mosquitoes – On-site and regional health impacts on future residents within the proposed Keralup development site.

There are significant issues of managing water quality and drainage within the Masterplan area that have not been addressed at this time. The assumptions made on improving water quality not only on-site but within the Serpentine River are not supported by technical modelling or within relevant Western Australian scientific literature. Current research points to a likely significant increase in the application of fertiliser and hence nutrient loading of the Serpentine River and the Estuary due to the urbanisation of the catchment. Therefore, to ensure that the water quality targets set

31

out in the draft WQIP are not exceeded it is the EPA’s expectation that there would be no net export of nutrients from the Keralup site.

The concept of using a constructed wetland to reduce significantly the nutrient load in the Dirk Brook and therefore in the Serpentine River is also not supported by current Western Australian research. Considering the likely increase in phosphorus input under an urban zoning, studies suggest that any phosphorus reduction provided by a constructed wetland along the Dirk Brook may be negligible. In addition, it is anticipated that despite the removal of all current nutrient load, water quality would not significantly improve for another 20-50 years due to the historical nutrient soil store on-site. This is likely to cause a significant amenity issue for residents living adjacent to the Serpentine River as the frequency and severity of algal blooms may increase.

Managing drainage across the site also poses a significant challenge. Paradoxically, following drainage/stormwater best practice within the Masterplan area has the potential to increase existing water quality issues within the Serpentine catchment and the broader Peel-Harvey Estuary. Within this context, it is imperative that all surface and groundwater studies relating to drainage and nutrient management on site are completed in advance of any further planning. The collection of baseline data would be essential to accurately determine the feasibility of any urban development on this site. Available information suggests that that the current export of nutrients from the Keralup site would significantly increase should this property be rezoned and developed for urban purposes. Even taking into account the Dirk Brook Living Stream Concept, there would still be a net export of phosphorus and other nutrients to the Serpentine River which is not considered acceptable in terms of achieving a reduction under the draft WQIP. Because of the unique conditions on this site including historical nutrient loads in the soil, soils that have a low capacity to retain nutrients and a waterlogged soil profile, standard development methodologies if applied to this site would not achieve the water quality objectives set out in the draft Water Quality Improvement Plan (WQIP). An innovative approach to solving these critical issues would be essential to reach an acceptable outcome. In relation to the other environmental issues relevant to the proposed development such as wetlands, remnant vegetation, soil and groundwater contamination, significant fauna, noise and odour, further investigations would be required to determine whether development is appropriate for some areas of the site. In particular, possible land use incompatibilities with surrounding land uses such as a piggery and several airfields could impact on the health and amenity of future residents and could preclude development from portions of the Masterplan area, affecting the form of development and this in turn may have consequential impacts on broader design objectives for the future Keralup. Should Government decide to develop this site then further substantial environmental investigations would need to be carried out as well as extensive liaison with all relevant technical agencies.

32

Appendix 1

References

Appleyard, S. personal communication. September 2007. ATA Environmental (2006) Environmental Appraisal Proposed Residential Development of Amarillo Farm in Karnup. Prepared for the Department of Housing and Works. June 2006. Bowman Bishaw Gorham. (1993) Potential Constraints of Wandalup Piggery. Prepared for Homeswest. July, 1993. Department of Environment and Heritage. (2005) Background Paper to the Wildlife Conservation Plan for Migratory Species, Department of Environment and Heritage, Canberra, Australian Capital Territory. Department of Water 2004 – 2007. (2007) Stormwater Management Manual for Western Australia, Department of Water, Perth, Western Australia. Environmental Protection Authority. (2006) Position Statement No. 9 Environmental Offsets Environmental Protection Authority, Perth, Western Australia, January 2006. Environmental Protection Authority. (2007). Draft Water Quality Improvement Plan for the Rivers and Estuary of the Peel-Harvey System. Environmental Protection Authority, Perth, Western Australia. GHD (2007) Report for Liege Street Wetlands. Performance Report 2005 to 2006. Report prepared for Swan River Trust. Government of Western Australia, (2000) Bush Forever – Keeping Bush in the City. Western Australian Planning Commission, Perth, Western Australia. Hill, A.L, Semeniuk, C.A, Semeniuk, V and Del Marco, A. (1996) Wetlands of the Swan Coastal Plain Vol 2A and 2B. Department of Environmental Protection/Water and Rivers Commission, Perth, Western Australia. Humphries, R and Robinson, S. (1995) Assessment of the Success of the Peel-Harvey Estuary System Management Strategy – A Western Australian attempt at Integrated Catchment Management. Water Science Technology Vol 32, No. 5-6. pp 255-264. Kelsey, P. (2001) Nutrient Export in Surface Water and Groundwater under Various Landuses. Proceedings of land Development in Areas of High Water Table Forum. Institute of Engineers, Australia, Hydrology and Resources Panel in association with the Urban Development Institute of Australia. Kelsey, P. (2005) Nutrient Pollution and Treatment in the Ellenbrook Catchment. Water and Rivers Commission, Perth, Western Australia. Kelsey, P and Zammit, C. (2003) LASCAM modelling of the urban development proposed in the Southern River-Forrestdale-Brookdale-Wungong Structure Plan. Volume 1 Department of Environment, Perth, Western Australia.

Kitsios, A and Kelsey, P. (2008) Nutrient Survey of Urban Areas in Coastal Catchments of Western Australia. Department of Water, Perth, Western Australia. Maunsell (2006) Amarillo Develoment Geotechnical Investigation. Unpublished report prepared for Taylor Burrell Barnett. Summers, R.N, Van Gool, D, Guide, N.R, Heady, G.J and Allen, T. (1999) “The Phosphorus content in run-off from coastal catchments of the Peel Inlet and Harvey Estuary and its associations with land characteristics”. Agriculture, Ecosystems and Environment, 73: 271-279. Trudgen, M. (1993) Vegetation and Flora Conservation Values at Homeswest’s Amarillo property. Unpublished report for Bowman Bishaw Gorham, November 1993 Western Australian Planning Commission, (2007) Acid Sulfate Soils Planning Bulletin No. 64, Perth, Western Australia, May 2007. Zammit , C and Summers, R. (2005). Modelling Catchment Processes in the Peel-Harvey Basin. 3rd WA State Coastal Conference 15 November 2005.